import Repl from '@/repl/Repl.tsx';
import CodeLink from '@/mdx-components/CodeLink.tsx';

# has()

Returns true if the key is defined in the provided collection.

<Signature code={`has(collection, key): boolean;`} />

A functional alternative to `collection.has(key)` which will also work with plain Objects and Arrays as an alternative for `collection.hasOwnProperty(key)`.

<Repl defaultValue={`has(['dog', 'frog', 'cat'], 2);`} />
<Repl defaultValue={`has(['dog', 'frog', 'cat'], 5);`} />
<Repl defaultValue={`has({ x: 123, y: 456 }, 'x');`} />
<Repl defaultValue={`has({ x: 123, y: 456 }, 'z');`} />
